Create A Validation Rule To Check That A Contact Is In The Zip Code Of Its Account.

create a validation rule to check that a contact is in the zip code of its account salesforce?

I am continuously getting an error called create a validation rule to check that a contact is in the zip code of its account salesforce below is my code

AND(ISBLANK( Id ), OR( MailingPostalCode = Account.postalcodeshipping ))